1. Technical Field
The present invention relates to a method for manufacturing a piezoelectric resonator, and particularly to a method for manufacturing a piezoelectric resonator having a micro groove in its arm.
2. Related Art
As smaller configurations have been adopted for electronic devices in recent years, there is a need for smaller electronic parts embedded in these devices.
Conventionally, a groove is formed on the arm of a piezoelectric resonator so as to decrease crystal impedances as well as increasing electromechanical coupling factors in order to attain smaller configurations (see Japanese Unexamined Patent Publication No. 2001-185987, for example).
While etching can be used for forming a groove on the arm, it is known that a groove with a desired cross sectional shape is hard to form since crystal has an anisotropic structure. In order to solve this problem, dry etching methods have been proposed to attain a desired cross sectional shape (see Japanese Unexamined Patent Publication No. 8-242134, for example).
The conventional technique that is disclosed in Japanese Unexamined Patent Publication No. 8-242134, however, involves the problem of the slow pace of dry etching. Moreover, it is difficult to improve processing efficiency because of the number of photolithography steps prior to the dry etching process, which has yet to be solved.
In consideration of the above-mentioned problems, the present invention aims to provide a method for manufacturing a piezoelectric resonator that is capable of accurately forming a groove of a desired shape in simplified steps in a short period of time.